The above-mentioned problems with telecommunications systems and other problems are addressed by the present invention and will be understood by reading and studying the following specification. A telecommunications network is described which uses a ring of ring switches to provide a backbone transport mechanism for data packets that is transparent to the data and protocols contained in the data packets. The ring switches can include a number of different features, alone or in combination, to implement this backbone network. Ring switches with such features are described in detail in the U.S. Pat. No. 6,154,462, entitled Circuits and Methods for a Ring Network, issued on Nov. 28, 2000, and in Section III below. The ring switches include, but are not limited to the following:
1. A ring switch in which packets are switched on to a unidirectional ring based on comparing a destination identifier, which may already be in the packet, to a table in the ring switch.
2. A ring switch in which packets are switched off and removed from the unidirectional ring based on comparing a destination identifier, which may already be in the packet, to a table in the ring switch thus freeing bandwidth for use by other devices and switches on the ring.
3. A ring switch in which packets received from a unidirectional ring, are placed back on the unidirectional ring based on comparing a destination identifier, which may already be in the packet, to a table in the ring switch.
4. A ring switch in which packets which have traveled completely around the ring are terminated by comparing a source identifier which may be already in the packet to a table, a switch identifier that was added by the ring switch to a table, or a hop counter that has reached a threshold value.
5. A ring switch in which no modification is made to the original packet in order to cause the packet to transmit from the local ports of one ring switch, around the ring to the local ports of another ring switch because the destination identifiers used to compare to the table are already contained in the original packet.
6. A ring switch in which no modification is made to the original packet in order to cause the packet to be terminated when the packet has traveled completely around the ring because the source identifiers used to compare to the table are already contained in the original packet.
7. A ring switch in which the tables are built automatically (self learned) by virtue of reading the source identifiers of each packet received by the ring switch.
8. A ring switch in which the original packet is modified slightly by the ring switch when placing the packet on a unidirectional ring by the addition of a switch identifier such that when the packet has traveled completely around the ring and back to the originating ring switch, the packet is terminated by detecting its own switch identifier.
9. A ring switch in which the original packet is modified slightly by the ring switch when placing the packet on the unidirectional ring by the addition of a counter, such that when the packet passes through each ring switch, the counter is incremented (or decremented) and the packet is terminated by any switch when the counter reaches a selected value.
This transport mechanism is simple and low cost to implement. Such networks can carry, for example, data to and from the Internet to a subscriber with a cable modem hook-up to a cable network or a DSL modem hook-up to a copper wire DSL network.